sanitize removes newlines and control characters from strings to prevent log injection

nextRequestID generates a cryptographically random request ID

rateLimit applies a simple per-server rate limit

recovery recovers from panics and logs them, preventing server crashes

securityHeaders adds security-related HTTP headers to all responses

BenchmarkNextRequestID benchmarks the request ID generation

BenchmarkRateLimiter benchmarks the rate limiter

BenchmarkSanitize benchmarks the sanitize function

TestHealthz tests the health check handler

TestIndex tests the index handler

TestIntegrationFullStack tests the full middleware stack

TestLoggingMiddleware tests the logging middleware

TestMinFunction tests the min helper function

TestNextRequestID tests the request ID generation

TestRateLimitMiddleware tests the rate limit middleware

TestRateLimiter tests the rate limiter

TestRecoveryMiddleware tests the panic recovery middleware

TestResponseWriter tests the response writer wrapper

TestSanitize tests the sanitize function

TestSecurityHeaders tests the security headers middleware

TestTracingMiddleware tests the tracing middleware